Cherokee, a 7-8 year old Quarter Horse mare, was brought in with her 6-8 week old foal, Sapphire.
Police launched an inquiry last week following the discovery of a blood-smeared van which was found to contain the meat of a butchered horse in cooler boxes.
A subsequent search revealed a carcass several blocks away, near the corner of Northwest 131st Ave and 182nd Street.
The killing was the latest in a string of more than 20 horse deaths which have angered residents of southern Florida.
Police believe the animals are butchered as part of a lucrative black-market trade in horse meat, which can fetch up to $US20 a pound.
Police arrested the owner of the van and an acquaintance, but the pair have been charged with loitering and prowling.
No charges have been brought in respect of horse slaughter.
However, ongoing police investigations into the case led to a farm, where the South Florida SPCA was called to uplift four horses.
"The foal, only six to eight weeks old, had already been taken away from her mother," the SPCA said.
"All four horses were transported to the South Florida SPCA Rescue ranch where they are currently receiving medical care, food and tender loving care.
"All four horses should make a full recovery. Also removed from the property was a tiny baby lamb."